stephen l. doggett senior hospital scientist department of medical entomology institute for clinical...
TRANSCRIPT
Stephen L. DoggettStephen L. DoggettSenior Hospital ScientistSenior Hospital Scientist
Department of Medical EntomologyDepartment of Medical EntomologyInstitute for Clinical Pathology & Medical Research, Institute for Clinical Pathology & Medical Research,
Westmead Hospital, Westmead NSW 2145Westmead Hospital, Westmead NSW 2145
Ticks – introductionTicks – introduction
Biology/ecology/lifecycleBiology/ecology/lifecycle
ManagementManagement
AvoidanceAvoidance
OverviewOverview
Worldwide – about 800 sp.Worldwide – about 800 sp. Australia – 75 (~15 attack humans)Australia – 75 (~15 attack humans) 2 groups – Soft & Hard ticks2 groups – Soft & Hard ticks
Most important - Most important - Ixodes holocyclusIxodes holocyclus Paralysis tick, scrub, bush, shell back Paralysis tick, scrub, bush, shell back Seed, grass (larval stage)Seed, grass (larval stage)
TicksTicks
1988-2013: 671 specimens1988-2013: 671 specimens AmblyommaAmblyomma: 3.7%: 3.7% AponommaAponomma: 0.3%: 0.3% HaemaphysalisHaemaphysalis: 1.8%: 1.8% RhipicephalusRhipicephalus: 1.3%: 1.3% IxodesIxodes: 93% : 93%
Ixodes holocyclus:Ixodes holocyclus: (98%) (98%) Adults: 37%, Nymph: 26%, Larvae: 37%Adults: 37%, Nymph: 26%, Larvae: 37%
Tick Samples to DMETick Samples to DME
1mm
LarvaLarvaNymphNymph
AdultAdultMaleMale
AdultAdultFemaleFemale
Tick Life CycleTick Life Cycle
Paralysis tick,Paralysis tick,
Ixodes holocyclusIxodes holocyclus
3m
0.5m
Host Seeking Host Seeking BehaviourBehaviour
Most of the yearMost of the year
Survival dependant on humiditySurvival dependant on humidity
Most activeMost active:: Following rainFollowing rain Periods of high humidityPeriods of high humidity
Larvae far more common than other stagesLarvae far more common than other stages High mortality in larval stage to nymphHigh mortality in larval stage to nymph
When are ticks active?When are ticks active?
Animal HostsAnimal Hosts
Red-necked Wallaby
House Mouse
Magpie
Australian Raven
Domestic Fowl
Human
Dog
Cat
Pig
Eastern Grey Kangaroo
Norwegian Rat
Bush Rat
Grasslands Melomys
Water Rat
Crimson Rosella
Pied Butcherbird
Echidna
Common Dunnart
Feathertail Glider
Red-legged Pademelon
Northern Brown Bandicoot
Southern Brown Bandicoot
Long-nosed Bandicoot
Mountain Brushtail Possum
Common Brushtail Possum
Brush-tailed Phascogale
Koala
Swamp Wallaby
Rabbit
Black Rat
After Roberts (1970)
Main Host Main Host BandicootBandicoot
MAKE SURE MAKE SURE YOU REMOVE YOU REMOVE THE HEAD!!!THE HEAD!!!
Tick RemovalTick Removal
Cultural Control: Cultural Control: Behaviour modificationBehaviour modification
Physical Control: Physical Control: Exclusion fencingExclusion fencing
Biological ControlBiological Control Parasites/pathogens/predatorsParasites/pathogens/predators Host removalHost removal Habitat modificationHabitat modification
Chemical ControlChemical Control RepellentsRepellents Habitat treatmentHabitat treatment Host treatmentHost treatment
Tick ManagementTick Management
Tick Control MethodsTick Control Methods
Habitat Modification
Fire
Host Removal
Chemical Treatment
Personal Protection
Con
trol
Dur
atio
nE
nvironmental Im
pactControl Method
Avoid ticky habitatAvoid ticky habitat
Avoid good ticky timesAvoid good ticky times After rain, high humidityAfter rain, high humidity
Wear light coloured clothingWear light coloured clothing
Check oneself regularly during & afterCheck oneself regularly during & after
Tuck pants into socks, shirts into pantsTuck pants into socks, shirts into pants
Remove clothing, place into hot dryerRemove clothing, place into hot dryer
Use repellents/permethrin on clothingUse repellents/permethrin on clothing
Cultural ControlCultural Control
FormulationsFormulations
GimmicksGimmicks
Australian Pesticides & Veterinary Australian Pesticides & Veterinary Medicines AuthorityMedicines Authority(National Registration Authority: NRA)(National Registration Authority: NRA)
For insecticides/repellents, assess:For insecticides/repellents, assess: Human ToxicityHuman Toxicity Product EfficacyProduct Efficacy Environmental ImpactsEnvironmental Impacts
APVMAAPVMA
ActiveActive
Approved useApproved use
Registered?Registered?
DirectionsDirections
DEET (N,N-Diethyl-meta-toluamide)DEET (N,N-Diethyl-meta-toluamide) PicaridinPicaridin Lemon Eucalyptus Oil (PMD)Lemon Eucalyptus Oil (PMD) IR3535IR3535 Citronella, melaleuca oilCitronella, melaleuca oil
Repellent ActivesRepellent Actives
““Natural”Natural”“Organic”“Organic”
““Safe” & Safe” & “Effective”“Effective”==
ActiveActive %% Protection TimeProtection Time
Repellent EfficacyRepellent Efficacy MosquitoesMosquitoes
Fradin & Day, NEJM (2002)Fradin & Day, NEJM (2002)
ActiveActive %% Protection TimeProtection Time
DEETDEET 24%24% 302m302m
ActiveActive %% Protection TimeProtection Time
DEETDEET 24%24% 302m302m
DEETDEET 20%20% 234m234m
ActiveActive %% Protection TimeProtection Time
DEETDEET 24%24% 302m302m
DEETDEET 20%20% 234m234m
DEETDEET 6.7%6.7% 112m112m
ActiveActive %% Protection TimeProtection Time
DEETDEET 24%24% 302m302m
DEETDEET 20%20% 234m234m
DEETDEET 6.7%6.7% 112m112m
CitronellaCitronella 10%10% 20m20m
ActiveActive %% Protection TimeProtection Time
DEETDEET 24%24% 302m302m
DEETDEET 20%20% 234m234m
DEETDEET 6.7%6.7% 112m112m
CitronellaCitronella 10%10% 20m20m
CitronellaCitronella 5%5% 14m14m
ActiveActive %% Protection TimeProtection Time
DEETDEET 24%24% 302m302m
DEETDEET 20%20% 234m234m
DEETDEET 6.7%6.7% 112m112m
CitronellaCitronella 10%10% 20m20m
CitronellaCitronella 5%5% 14m14m
Citronella (WB)Citronella (WB) 25%25% 0.2m0.2m
PermethrinPermethrin = toxicant not a repellent = toxicant not a repellent
Two formsTwo forms:: DIY, ‘dip’ clothingDIY, ‘dip’ clothing Impregnated fabrics (IF)Impregnated fabrics (IF)
Studies show:Studies show: IF better protection than DIYIF better protection than DIY IF more washes than DIYIF more washes than DIY IF less environmental impactsIF less environmental impacts Permethin better protection than repellentsPermethin better protection than repellents Widely used by armiesWidely used by armies
Permethrin Impregnated ClothingPermethrin Impregnated Clothing
Permethrin Impregnated Clothing?Permethrin Impregnated Clothing?
Human SafetyHuman Safety Risk analysisRisk analysis
What is worse: bites or repellents?What is worse: bites or repellents?
DEET first registered, 1957DEET first registered, 1957 Billions of usesBillions of uses Recommended by WHO & CDCRecommended by WHO & CDC Only product recommended by CDCOnly product recommended by CDC US EPA: adverse reactions 1:100millionUS EPA: adverse reactions 1:100million
EPA: EPA: ““permethrin factory-treated clothing is unlikely to permethrin factory-treated clothing is unlikely to pose any significant acute or chronic hazard to peoplepose any significant acute or chronic hazard to people””
Read & heed the label!Read & heed the label!
Host Exclusion FencingHost Exclusion Fencing
Reduce overhanging foliageReduce overhanging foliage
Clearing brush/bushesClearing brush/bushes
Removal of leaf litter/mulchRemoval of leaf litter/mulch
Maintain lawns <15cmMaintain lawns <15cm
CementingCementing
Inc. sunlight to ground, dec. humidityInc. sunlight to ground, dec. humidity
Achieves most prolonged level of controlAchieves most prolonged level of control
Habitat ModificationHabitat Modification
AdvantagesAdvantages Rapid control, 97% within 24 hoursRapid control, 97% within 24 hours Cost effectiveCost effective Less environmental damageLess environmental damage
DisadvantagesDisadvantages Not tick specificNot tick specific Relatively short termRelatively short term
Pyrethroids: Pyrethroids: Permethrin, Betacyfluthrin, Permethrin, Betacyfluthrin, BifenthrinBifenthrin
Chemical ControlChemical Control
PyrethroidPyrethroid
Toxic to lower vertebratesToxic to lower vertebrates
Strongly binds to the soilStrongly binds to the soil reduced contamination riskreduced contamination risk
Recommended by WHO for mosquito c.Recommended by WHO for mosquito c.
BUT DOES IT WORK?BUT DOES IT WORK?
Two formulationsTwo formulations:: Emulsifiable Concentration, GranularEmulsifiable Concentration, Granular
BifenthrinBifenthrin
Bifenthrin - FormulationsBifenthrin - Formulations
Granular Granular (Bithor, Brigade, Vigilanti)(Bithor, Brigade, Vigilanti)
Can be used against all stagesCan be used against all stages
Directions for use:Directions for use:““Applications should be made in the spring to control Applications should be made in the spring to control
larvae and nymphs that reside in the soil and leaf larvae and nymphs that reside in the soil and leaf litter…”litter…”
ApplicationApplication::
Hand, fertilizer spreaders, Hand, fertilizer spreaders,
backpack, aerialbackpack, aerial
WE WANT WE WANT YOUR YOUR TICKS!TICKS!
www.medent.usyd.edu.auwww.medent.usyd.edu.au